Pseudorotaxanes and rotaxanes in the Chemistry curriculum for undergraduate students: A gateway to modern molecular design

Abstract

Design and synthesis of a 24-membered macrocyclic wheel (MC) based [2]rotaxane (ROT) with multiple functional groups are reported. Threading followed by capping strategy has been used to form a mechanically interlocked structure. Initially, metal ion template [2]pseudorotaxane is formed via ternary complexations. Thereafter, stoppering via Click Chemistry results in [2]rotaxane. The interlocking nature has been established by ESI-MS spectrometry and various 1D and 2D NMR studies. This concept also offers a valuable pedagogical framework for teaching and learning modern chemical design strategies and, the interpretation of various spectroscopic and spectrometric data, along with extensive use of Chem-Draw software for undergraduate students. This article explores the design, synthesis and characterization of pseudorotaxane and rotaxane, importance of interlocked systems in the pedagogy at undergraduate level while aiming towards deeper understanding of modular synthesis and orthogonal reactivity.